Currently performed researches of the effectiveness of power generating units have shown that significant power losses occurs caused by some reasons including the increased thermal pressure on account of forming solid (mainly carbonate) and soft (organic and oozy) sediments in condenser pipes.
An analysis of the background of the invention has shown that the existed problem consisting in cleaning the internal surfaces of the pipes, including condenser pipes, from the solid sediments is solving by a plurality of methods implemented in particular devices.
All the variety of known means for cleaning may be divided into two main groups: chemical and mechanical ones.
The essence of the chemical methods for cleaning consists in the preparing the solution of the caustic soda or hydrochloric acid, supplying the prepared solution to the pipe cavity being cleaned, and subsequent washing the pipes.
Chemical methods for cleaning allow to clean the internal surface of the pipes from the solid carbonate sediments but they characterized by the following drawbacks:
corrosion of the metal of cleaned surfaces; PA1 possibility of the pollution of the environment; PA1 toxicity of applied reagents; PA1 high cost of used reagents and equipment. PA1 l is a distance between rollers, PA1 d.sub.p is an internal diameter of the pipe, roller heads being shifted in an axial direction relative to each other, and bores for supplying the fluid being made in communication, one bore is coaxial with the longitudinal axis of the housing and the second bore is on its external surface, and the other end surface of the housing is coupled to the rotation drive of the housing through the holder by means of the flexible communication. PA1 n is a number of roller heads. PA1 k is a number of rollers in the head, PA1 t is a thickness of solid sediments.
All the variety of known mechanical means for cleaning may be divided into cleaning the pipes continuously during operation and cleaning the pipes periodically.
A method for cleaning the internal surface of pipelines from the solid sediments by using the washing-out ability of the high pressured fluid stream is known, wherein the pressure difference is produced for dividing the fluid flow in the pipeline into two streams, one of which is used in the turbine for transforming the other stream into a high pressure stream, and then both streams are directed towards the internal surface of pipeline and moved along it by the spiral line (USSR Author's Certificate .sup.1 268103, Int.C1.6 B 08 B 9/04, 1968).
Another method for cleaning the internal surface of pipeline is known, said method being executed by means of treating the internal surface of the pipe with a cleaning device rotated within the pipe by affecting that device with the pressure of the working agent flow orienting it towards the movement of the cleaning device, the contact of the latter with the internal surface of pipeline is carried along the spiral line, the direction of which step is opposite the flow movement while moving it in the direction of the cleaning device rotation (USSR Author's Certificate .sup.1 1243846, Int.C1.6 B 08 B 9/04, 1984).
Yet another methods for periodical cleaning are known, wherein, before the cleaning, the cavity is blown through by a pistol first with the water and then with the air, and at the ends of pipes a beginning bore is made with a reamer in solid sediments to pass a cleaning element through them. After this the cleaning element is placed into the formed beginning bore and moved by supplying the water under the pressure of 2 to 6 atm within the cavity being cleaned. Sediments are cut off during the interaction with cutting edges of the cleaning element. The cleaning element is done as three or four split bushings placed on the rod, the cutting edges of those bushings having different diameters increasing in the direction opposite the direction of the cleaning element movement. Such a technology is used by Conco (Conco Systems, Inc., 1995, Printed in U.S.A.).
An analogous technology is used by Arcor International Ltd. The difference from the described technology consists generally in the cleaning element used. It is formed as a brush made from the steel wire, moving in the pipe cavity being cleaned under the influence of a continuously supplied water and pulsingly supplied air.
A well-known method used by TAPROGGE may be referred as a method for continuous cleaning by pumping the fluid with inserted beads through the pipe cavity. Surfaces of the beads have spikes or are covered with the corundum coating or polishing material depending on the level of pipe clogging and the stage of the cleaning operation. During the circulation of beads in the pipe cavity and interaction with bead coating the sediments in a cavity being cleaned are destroyed and flown away by the fluid flow. As the beads become worn they are sifted out and removed from the cleaning process while passing through the unit of their size control.
In the analogous technology also known from the USSR Author's Certificate .sup.1 186929 Int.C1.6 F 28 G 1/12, B 08 B 9/04, 1984, the beads are made from a material which linear expansion coefficient is chosen larger than the expansion coefficient of the pipe material. As the pipe cavity becomes cleaner the temperature of the fluid pumped through it, is made higher which causes the temperature increase of the beads being in it, and therefore the increase of their diameter. This, in turn, allows to cut off the sediment products gradually, layer by layer, thereby increasing the quality and effectiveness of the cleaning.
Aforementioned technical decisions characterizing mechanical methods for cleaning solve partially problems existed in such technologies, but during the process of their realization, particularly when cleaning from solid carbonate sediments, the quality of such cleaning does not always meet the presented requirements. Moreover, the cases of damaging the internal surface of the pipe occur during the cleaning which leads to their rapid corrosion and to premature finishing their exploitation. A series of other inconveniences, for example, difficulties in removing the stopped cleaning elements (brushes, beads), and also a need to heat the passed fluid for increasing the bead size etc., stimulate actions for the further development of mechanical methods for cleaning.
The method, most close to the present invention by its technical essence and a result being achieved while its using, is a method for cleaning the internal surface of the pipes, which method consists in moving within the pipe cavity being cleaned a solid working body in the form of a pig placed with a gap relative to the walls of the pipe being cleaned for producing the cavitation and a pressure of the fluid working agent onto the end surface of the working body. A pressure of 70 to 700 kgf/cm.sup.2 is produced at the initial section of the pipe and maintained during the time period sufficient for passing the working body through the pipe cavity being cleaned.
After finishing one cleaning cycle, in the next cycle the working body is used of a size larger than in previous cycle, and the water is used as a fluid working body (USSR Patent .sup.1 1618277, Int.C1.6 B 08 B 9/04, F 28 G 1/13, published 1990).
The present method partially removes problems typical for the known method although its utilizing also doesn't provide the required quality of the cleaning. Moreover, it is necessary to have a sufficiently complex regime for setting up the interaction between the fluid working agent and the working body and some complexity in determining the optimal size of the working body.
A device for cleaning the internal surface in known consisting of a thrower having an axial opening for passing a fluid working agent, the thrower being positioned by the attachment mechanism, and a drive for the longitudinal movement of the thrower for supplying workings bodies into the pipe, a magazine for the working bodies, a high pressure source for the fluid working agent, means for controlling the movement of the thrower depending on the existence of the working body, the attachment mechanism of thrower including horizontal or vertical supporting guide elements positioned with a possibility to move relative to each other, and the horizontal or vertical supporting guide elements are provided with a supporting element for positioning at least one thrower.
Moreover, the device includes an adjusting means for changing the distance between the thrower and a pipe cavity being cleaned.
The device also has an additional means for positioning the driving element, which means includes a guide pipe and a power cylinder in which the thrower is positioned along the cylinder axis passing through the cylinder' piston and rigidly coupling with it, the guide pipe being positioned partially in the power cylinder housing and springed relatively to the internal surface of power cylinder, and partially behind the power cylinder housing for positioning on it the working bodies' magazine, and a sealing element is positioned on the free end of the pipe and springed relatively to the axis of the pipe for the incomplete sealing between the tip of the thrower and an end surface of the pipe being cleaned.
Means for controlling the thrower depending on the presence of the working body has sensors of the working body position placed on the guide pipe on the side opposite the magazine with working bodies (USSR Patent .sup.1 1618277, Int.C1.6 B 08 B 9/04, F 28 G 1/13, published 1990).
The known device is not sufficiently effective and it doesn't provide the required quality of the cleaning when cleaning the solid sediments.
The device, most close to the present invention by its technical essence and a result being achieved while using, is a device for cleaning the internal surface of the pipeline having a housing, a main turbine placed on the shaft coaxially with the housing and coupled with it, an additional turbine placed on the other end of the shaft with a possibility to rotate relatively to it, a water supply system, the additional turbine being provided with a spherical rim having cleaning elements placed on it, and a shaft section with the additional turbine is oriented at an angle to the housing axis (USSR Author's Certificate .sup.1 1013002, Int.C1.6 B 08 B 9/04, 1983).
However, the known device is not sufficiently effective, particularly, in cases of plugging the pipes with solid, carbonate sediments. The possibility of damaging the internal surface of pipes is not excluded and the design of the device doesn't allow to use it for cleaning of small diameter pipes.